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Flexible artificial synapse based on single-crystalline BiFeO_(3) thin film

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Nano Research 2022年第3期15卷 2682-2688页

作者： Zhen zhao Amr Abdelsamie rui Guo Shu Shi Jianhui zhao Weinan lin Kaixuan Sun Jingjuan Wang Junling Wang Xiaobing Yan Jingsheng Chen Key Laboratory of Brain-like Neuromorphic Devices and Systems of Hebei Province College of Electron and Information EngineeringHebei UniversityBaoding 071002China Department of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Department of Materials Science and Engineering National University of SingaporeSingapore 117576Singapore Department of Physics Southern University of Science and TechnologyShenzhen 518055China

Realization of functional flexible artificial synapse is a significant step toward neuromorphic ***,a flexible artificial synapse based on ferroelectric tunnel junctions(FTJs)is demonstrated,using BiFeO_(3)(BFO)thin film as the functional *** inorganic single crystalline FTJs grown on rigid perovskite substrates at high temperatures are integrated with the flexible plastic substrates,by using the water-soluble Sr_(3)Al_(2)O_(6)(SAO)as the sacrificial layer and the following *** transferred freestanding BFO thin film exhibits excellent ferroelectric ***,the memristive properties and the brain-like synaptic learning performance of the flexible FTJs are *** results show that multilevel resistance states were maintained well of the flexible artificial synapse,together with their stable synaptic learning *** work indicates the promising opportunity of ferroelectric thin film based flexible synapse used in the future neuromorphic computing system.

关键词： flexible ferroelectricity memristor artificial synapse

LEAST-SQUARES GALERKIN PROCEDURE FOR SECOND-ORDER HYPERBOLIC EQUATIONS

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Journal of Systems Science & Complexity 2011年第2期24卷 381-393页

作者： Hui GUO Hongxing rui Chao lin School of Mathematics and Computational Science China University of Petroleum Dongying 257061 China. School of Mathematics and System Science Shandong University Jinan 250100 China. Network and Education Technology Center China University of Petroleum Dongying 257061 China.

This paper proposes the least-squares Galerkin finite dement scheme to solve secona-oraer hyperbolic equations. The convergence analysis shows that the method yields the approximate solutions with optimal accuracy in （L2 （Ω））2 × L2 （Ω） norms. Moreover, the method gets the approximate solutions with second-order accuracy in time increment. A numerical example testifies the efficiency of the novel scheme. Key words Convergence analysis, Galerkin finite element, hyperbolic equations, least-squares, nu- merical example.

关键词： Convergence analysis Galerkin finite element hyperbolic equations least-squares nu-merical example.

Heterologous biosynthesis of medicarpin using engineered Saccharomyces cerevisiae

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Synthetic and Systems Biotechnology 2023年第4期8卷 749-756页

作者： Chujie Lu rui Du Hao Fu Jizhao Zhang Ming zhao Yongjun Wei Wei lin Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization NanjingChina School of Pharmacy Nanjing University of Chinese MedicineNanjingChina Key Laboratory of Advanced Drug Preparation Technologies Ministry of EducationSchool of Pharmaceutical SciencesZhengzhou UniversityZhengzhouChina Department of Pathogen Biology School of Medicine&Holistic Integrative MedicineNanjing University of Chinese MedicineNanjingChina Xinjiang Institute of Traditional Chinese Medicine and Ethnic Medicine UrumqiChina

Medicarpin is an important bioactive compound with multiple medicinal activities,including anti-tumor,anti-osteoporosis,and anti-bacterial *** is associated with pterocarpans derived from medicinal plants,such as Sophora japonica,Glycyrrhiza uralensis Fisch.,and Glycyrrhiza glabra ***,these medicinal plants contain only low amounts of ***,the planting area for medicarpin-producing plants is limited;consequently,the current medicarpin supply cannot meet the high demands of medicinal *** this study,eight key genes involved in medicarpin biosynthesis were identified using comparative transcriptome and bioinformatic *** vitro and in vivo enzymatic reaction confirmed the catalytic functions of candidate enzymes responsible for the biosynthesis of medicarpin and medicarpin *** engineering of these genes in Saccharomyces cerevisiae achieved the heterologous biosynthesis of medicarpin using liquiritigenin as a substrate,with a final medicarpin yield of 0.82±0.18 mg/*** increasing the gene copy numbers of vestitone reductase(VR)and pterocarpan synthase(PTS),the final medicarpin yield was increased to 2.05±0.72 mg/*** study provides a solid foundation for the economic and sustainable production of medicarpin through a synthetic biology strategy.

关键词： Medicarpin Glycyrrhiza glabra L. Saccharomyces cerevisiae Medicarpin biosynthesis pathway Transcriptome sequencing Pterocarpan

Robust Regression Analysis for Clustered Interval-Censored Failure Time Data

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Journal of Systems Science & Complexity 2021年第3期34卷 1156-1174页

作者： LUO lin zhao Hui School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China School of Statistics and Mathematics Zhongnan Univer'sity of Economics and LawWuhan 430064China

Clustered interval-censored failure time data often occur in a wide variety of research and application fields such as cancer and AIDS studies. For such data, the failure times of interest are interval-censored and may be correlated for subjects coming from the same cluster. This paper presents a robust semiparametric transformation mixed effect models to analyze such data and use a U-statistic based on rank correlation to estimate the unknown parameters. The large sample properties of the estimator are also established. In addition, the authors illustrate the performance of the proposed estimate with extensive simulations and two real data examples.

关键词： Clustered data interval-censoring random effects rank estimation semiparametric transformation models

Characteristics of a coherent jet enshrouded in a supersonic fuel gas

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International Journal of Minerals,Metallurgy and Materials 2020年第2期27卷 173-180页

作者： Fei zhao Rong Zhu Wen-rui Wang Key Laboratory of Fluid Interaction with Material University of Science and Technology BeijingBeijing 100083China National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanical Engineer University of Science and Technology BeijingBeijing 100083China

Based on a current coherent jet,this study proposes a supersonic combustion(SC)coherent jet in which the main oxygen jet is surrounded by a supersonic fuel *** characteristics of the proposed coherent jet are analyzed using experimental methods and numerical simulations in the high-temperature environment of electric arc furnace(EAF)*** SC coherent jet achieved stable combustion in the EAF steelmaking *** simulated combustion temperature of the supersonic shrouding methane gas was 2930 K,slightly below the theoretical combustion temperature of methane–oxygen *** high speed and temperature of the supersonic flame effectively weakened the interaction between the main oxygen jet and the external ambient gas,inhibiting the radial expansion of the main oxygen jet and maintaining its high speed and low turbulence over a long *** features improved the impact capacity of the coherent jet and strengthened the stirring intensity in the EAF bath.

关键词： EAF steelmaking coherent jet supersonic shrouding fuel gas supersonic combustion field characteristics

Dynamics of exciton energy renormalization in monolayer transition metal disulfides

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Nano Research 2020年第5期13卷 1399-1405页

作者： Jiaxin zhao Weijie zhao Wei Du rui Su Qihua Xiong Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China

Fundamental understandings on the dynamics of charge carriers and excitonic quasiparticles in semiconductors are of central importance for both many-body physics and promising optoelectronic and photonic ***,we investigated the carrier dynamics and many-body interactions in two-dimensional(2D)transition metal dichalcogenides(TMDs),using monolayer WS2 as an example,by employing femtosecond broadband pump-probe *** time regimes for the exciton energy renormalization are unambiguously revealed with a distinct red-blue-red shift upon above-bandgap optical *** attribute the dominant physical process in the three typical regimes to free carrier screening effect,Coulombic exciton-exciton interactions and Auger photocarrier generation,respectively,which show distinct dependence on the optical excitation wavelength,pump fluences and/or lattice *** intrinsic exciton radiative lifetime of about 1.2 picoseconds(ps)in monolayer WS2 is unraveled at low temperature,and surprisingly the efficient Auger nonradiative decay of both bright and dark excitons puts the system in a nonequilibrium state at the nanosecond *** addition,the dynamics of trions at low temperature is observed to be significantly different from that of excitons,e.g.,a long radiative lifetime of^108.7 ps at low excitation densities and the evolution of trion energy as a function of delay *** findings elucidate the dynamics of excitonic quasiparticles and the intricate many-body physics in 2D semiconductors,underpinning the future development of photonics,valleytronics and optoelectronics based on 2D semiconductors.

关键词： transitional metal disulfide exciton dynamics renormalization transient absorption spectroscopy carrier screening effect exciton-exciton interactions

Collapse of cavitation bubbles near air bubbles

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Journal of Hydrodynamics 2020年第5期32卷 929-941页

作者： Jing Luo Wei-lin Xu rui Li State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China

The cavitation erosion is one of the common damage modes in water *** study of the interaction among cavitation bubbles,air bubbles and the wall is of great significance for understanding the mechanism of the air entrainment to alleviate the cavitation and to enhance the cavitation erosion mitigation effect of *** using the high-speed camera,the regular patterns of the collapse of cavitation bubbles in the vicinity of the wall and the air bubbles are studied in this *** is shown that in the vicinity of air bubbles,the cavitation bubbles may only collapse towards or from air bubbles,while under the dual impacts of air bubbles and the wall,the direction of collapse of the cavitation bubbles depends on the combined vector of the impact forces of the air bubbles and the *** the air bubbles are very close to the cavitation bubbles,the air bubbles will be penetrated and stretched by the cavitation bubbles,when the distance between them is short enough,the cavitation bubbles and the air bubbles will connect to form gas-type cavitation bubbles,and the collapse strength will be significantly decreased,when there are two air bubbles near the cavitation bubbles,they may even be penetrated successively by the cavitation *** it can be concluded that during the air entrainment to alleviate the cavitation,the number of air bubbles is more important than the total air concentration.

关键词： Cavitation bubble air bubble high-speed photography air entrainment to alleviate cavitation

Effect of tungsten oxide on ceria nanorods to support copper species as CO oxidation catalysts

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Journal of Rare Earths 2021年第1期39卷 43-50,I0002页

作者： Yu'nan Li lin Gan rui Si Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials and School of Material Science and EngineeringHubei UniversityWuhan 430062China Zhangjiang Laboratory Shanghai Synchrotron Radiation FacilityShanghai 201204China

In this work,tungsten oxide with different concentrations(0,0.4 at%,2.0 at%and 3.2 at%)was introduced to the ceria nanorods via a deposition-precipitation(DP)approach,and copper species of ca.10 at%were sequentially anchored onto the modified ceria support by a similar DP *** aim of the study was to investigate the effect of the amount of tungsten oxide(0,0.4 at%,2.0 at%,and 3.2 at%)modifier on the copper-ceria catalysts for CO oxidation reaction and shed light on the structure-activity *** the aids of multiple characterization techniques including N2 adsorption,high-resolution transmission electron microscopy(HRTEM),powder X-ray diffraction(XRD),X-ray absorption fine structure(XAFS),and temperature-programmed reduction by hydrogen(H2-TPR)in combination with the catalytic performance for CO oxidation reaction,it is found that the copper-ceria samples maintain the crystal structure of the fluorite fcc CeO2 phase with the same nanorod-like morphology with the introduction of tungsten oxide,while the textural properties(the surface area,pore volume and pore size)of ceria support and copper-ceria catalysts are changed,and the oxidation states of copper and tungsten are kept the same as Cu2+and W6+before and after the reaction,but the introduction of tungsten oxide(WO3)significantly changes the metal-support interaction(transfer the CuOx clusters to Cu-[Ox]-Ce species),which delivers to impair the catalytic activity of copper-ceria catalysts for CO oxidation reaction.

关键词： Copper catalyst Ceria Tungsten oxide CO oxidation Structure-activity relationship Rare earths

A smart DNA nanodevice for ATP-activatable bioimaging and photodynamic therapy

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Science China Chemistry 2020年第10期63卷 1490-1497页

作者： Bei Liu rui Ma Jian zhao Yuliang zhao Lele Li School of Science Minzu University of ChinaBeijing 100081China CAS Key Laboratoty for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience National Center for Nanoscience and TechnologyBeijing 100190China College of Materials Science and Optoelectronic Technology University of Chinese Academy of SciencesBeijing 100049China GBA Research Innovation Institute for Nanotechnology Guangdong 510700China

Rational design of activatable photosensitizers for controlled generation of singlet oxygen remains a challenge for precise photodynamic therapy(PDT).Herein,we present an aptamer-based nanodevice for adenosine 5′-triphosphate(ATP)-activatable bioimaging and *** nanodevice is constructed by modifying ATP-responsive duplex DNA units and polyethylene glycol on the surface of a gold nanoparticle(AuNP)through the thiolate-Au *** DNA units were designed by the hybridization of the ATP aptamer strand with a methylene blue(MB)-modified complementary DNA(cDNA).The close proximity of MB to the surface of AuNP results in the low photodynamic activity of MB(OFF state).Once internalized into cancer cells,the ATP-binding induced conformation switch of aptamer strand leads to the release of the MB-bearing DNA strand from AuNPs,resulting in the activatable generation of singlet oxygen under light irradiation(ON state).We demonstrate that the DNA nanodevice represents a promising platform for ATP-responsive bioimaging and specific PDT in vitro and in *** work highlights a potential way for specific tumor diagnosis and therapy.

关键词： DNA nanotechnology ATP-activatable photodynamic therapy bioimaging